Timing mechanism



M 1950 M. H. KAEFER EI'AL 2,502,220

I 'riumc MECHANISM Filed Jan. 17, 4946 3 Sheets-Sheet 1 lILIIIIIIIIIIIIIIIILMII m:

M/QRT/N H. KQEFER EVERETT 5. E/QSSETT March 28, 1950 M. H. KAEFER ETAL TIMING IIECHANISII 3 Sheets-Sheet 2 Filed Jan. 1'7, 1946 FQWEnNTO 5 M/QRT/N H. KHEFER EVERETT \5. BHSSETT Q fl-r-roarvay Patented Mar. 28, 1950 TIMING MECHANISM Martin H. Kaefer, Thomaston, and Everett S.

Bassett, Waterbury. Conn., assignors to General Time Corporation, a corporation of Dela ware Application January 17, 1946, Serial No. 641,665

2 Claims. (Cl. 161--1) This invention relates to timing devices for controlling the supply of electricity or fuel to stoves and other instruments where the interval of heat supplied requires regulation.

Among other objects the invention aims to provide improved single cycle automatic interval control. 1 r

Another object is to provide mechanism for controlling .the operation of ovens and the like which minixnizesthe" attention and skill required for setting the mechanism for a heating cycle.

A still further'object is to provide improved sequencecontrol mechanism to insure proper setting of the control devices.

Other objects and advantages will become apparent from the following description of one apparatus embodying the invention and illustrated in the accompanying drawings.

In said drawings:

Figure 1 is an elevation of the control panel showing the control clock and the combined main switch and thermostat control.

Figs. 2, 3 and 4 are e evations illustrating the self-deleting control dials in successive phases.

Fig. 5 is a plan view t ken approximately on the plane 5-5 of Fig. 1 of the thermostat control and operating motor.

Fig. 6 is an elevation taken approximately on the plane 3-6 of Fig. 1 of the time control mechanism.

Fig. '7 is a sectional elevation thereof taken on the plane 1-! of Fig. 6.

Fig. 8 is a plan view of sequence control mechanism.

Fig. 9. is a sectional elevation thereof on the plane 3-9 of Fig. 8.

Fig. 10 is a fragmentary perspective view showing details of the cycle interrupting mechanism.

Fig. 11 is an enlarged sectional view taken approximately on the plane illl of Fig. 10 illustrating the operation of the cycle interrupting mechanism.

Fig. 12 is a sectional view taken on the plane 13-42 of Fig. 7 showing on an enlarged scale the starting switch and associated mechanism.

Fig. 13 is a simplified diagram of the electric system and its controlling mechanism.

Theinvention is here embodied in a mechanism for controlling e ectric heating elements in stoves and the like but it will be apparent that it has utility in the cycle control of other devices. The apparatus is illustrated as controlling the time cycle of a thermostatically regulated range or oven heating element represented diagrammatically at ll (Fig. 13). The thermostat ii is taken controlled by conventional regulator knob 12 (Figs. 1 and 13) which functions not only to set the thermostat but when rotated beyond the bottom of the temperature scale i3 to open the main switch H to cut off current from the heating element It. The illustrative thermostat regulating mechanism [5 is of the well-known type wherein a flexible belt cable I! or the like operates the rotatable regulator drum l9 from the drum 2| on knob l2 accessibly' located on the control panel 22.

As is well understood, setting of the thermostat knob ii. at a desired t mperature (to be maintained by the thermostatic regulator) automatically closes the main switch [4. In this instance, another switch 25 is placed in the heater circuit 26 to control the automatic starting of the cycle as presently described. The setting of the thermostat knob to the desired temperature to be maintained automatically closes main switch II. The mechanism for closing switch 25 to start the cycle is, in the present case, time controlled by clock mechanism indicated generally at 28 (Fig. 6) represented by a conventional synchronousmotor driven electric clock, the details of which are well-known and which form no part of this invention. The switch-control mechanism operates to op n switch 25 and hold the same open until the time at which it is'desired to start the tional construction and in this case comprises a rotating graduated dial 33 (carrying a start index 34) driven by gear 35, and a companion dial element 36 (driven by gear 31) partly overlying dial 33 and covering the graduations representin the elapsed portion of the heating cycle.

Element 36 is rotatab e on clock dial 38 to regis ter its index 40 with the desired end of the cycle.

The cycle begins when the clock driven clutch 29 has rotated to engaging-position with gear 35 which drives dial 33 as presently explained.

This occurs when the tip 39 of the clutch (which is axially slidable'on the shaft ll of' gear 3|) registers with and enters recess of slot 42 in gear 35 (Fig. 7). The clutch then drives gear 35 to a e. aql sdeleting wr stnd t axial movement Gil-311m 4| (which occurs upon such registry) permits the contacts 43 of switch 25 to close. In the present instance a spring 44 supplies (through lever 45) the force necessary to shift clutch 23 when the latter registers with the slot 42. Lever 45 is fulcrumed at 43 on the post 41 and straddles shaft 4| to bear against the hub 43 of gear 3|. The latter is driven by a broad faced clock driven gear 43 (Figs. 6 and i3) and thus remains in mesh therewith in both open and closed clutch positions.

Starting dial 33 and the overlying "stop" dial 33 are mounted on coaxial sleeve shafts i and 52 coaxial with and surrounding the conventional minute and hour clock hand shafts 53 and 54 (Fig. 13). Gears 55 and 53 on the inner ends of the sleeve shafts mesh respectively with driving ears 35 and 31.

Figs. 2. 3, 4 and 7 illustrate the functioning of the dials 33 and 33 during and after the cycle. As shown in Fig. 2, the start indicating dial 33 has been set by rotation of gear 5 to re i t r' the cycle is interrupted as presently ex lained.

The portion of the dial 33 remaining visible indicates the unfinished ortion of the cyce. As illustrated in Fig. 4, after completion of the cycle the dials with their indices in registry continue to rotate with the clock hour hand thereby visually indicating that the ap aratus is not functioning under automatic control.

In Fig. 7 appears another illustrative setting of the dials. The clock hands indicate the time as approximately 7:00. The startin index is set at 8:30 and the stop" index at 11:45.

Setting of the starting" controls (including switch 25) is effected in this instance by axially slidable shaft 53 extending beyond the front of the clock and carrying a setting knob 33. Shaft 53 carries a collar 8| adapted to bear a ainst lever 45 to shift clutch 23 to released position (Fig. 6). Movement of lever 45 by shaft 53 also simultaneously opens switch 25, the latter being connected to lever 45 by bracket 32. The present switch is in the form of a double pole switch wherein the blades I44 are connected by an insulating cross bar 34 to which bracket 32 is connected.

Shaft 53 also carries a wide-faced gear 33 constantly meshing with gear 33 and adapted to rotate the latter to set the starting dial 33 when the clutch element 33 has been withdrawn from engagement with gear 35. Until such disengagement, gear 35 is held against free rotation by being coupled with the clock train, thereby preventing inadvertent or accidental alteration of the setting. Switch 25 is held open by the extremity 33 of the clutch riding on the face of gear 35. The frictional contact of clutch element 33 with gear 35 is relatively light and imposes no substantial load on the clock mechanism. Switch contacts 43 close under the pressure of the spring element 44 when the starting time has been reached and the clock gear 3| has rotated the clutch element 33 into registry with the recess 42 in gear 35.

The control mechanism is advantageously designed so as not to be recycling. In the present case this is effected by automatically restoring the system to manual control by means of hand knob l2. at the end of an automatically con- 4 trolled cycle. Thus the operator is not obliged to remember to make a manual adjustment to prevent accidental and undesired closing of the heating circuit. Furthermore, manual control of the heating element is not defeated as in some apparatus by oversight on the part of the operstar to shift from automatic control to manual control.

In the present instance avoidance of recycling and automatic restoration to manual control is effected by terminating the cycle by operation of the main switch l4 and not by the opening switch 25 which remains closed until there is a deliberate resetting for another cycle. The cycle interrupting and associated mechanism is controlled by a settng device in the form of a knob 33 similar to knob 33 and carried at the end of a slidable shaft 51 which operates (in a manner similarly to shaft 53) a clutch 33 (similar to clutch 23) carrying a clutch element 33 slidable to engage gear 31 by entry into recess or slot H (F g. 7) therein, in a manner similar to the operation of clutch 23 in gear 35 (Fig. 12). Shaft 61 also carries a wide-faced gear 12 for rotating gear 31 to set stop dial 33 as above described when clutch element 33 has been retracted. Operation of the latter is effected through a lever 13 fulcrumed at 14 on post 41 and straddling the hub 13 of clock driven gear I1 driving clutch 63. Lever 13 also straddles shaft 31 and bears against collar 13 thereon. A spring 13 around shaft 31 bears on lever 13 to bias clutc 63 toward engagement with gear 31. Also 0 rated by shaft 31 through lever 13 s a control switch 3| (Figs. 10 and 11) for actuating opening of main switch l4. Switch contacts 32 are opened when shaft 61 is pushed inwardly to release clutch 63 and permit setting of the stop dial 33. Such contacts close upon termination of the heating cycle which occurs when clutch element 63 enters opening II in gear 31 thus permitting shaft 61 to move outwardly. Until such registry contact clutch extremity 33 bears against the face of gear 31 holding switch contacts 32 open.

The switch operating mechanism is here shown in the form of a lever 34 (Figs. 10 and 11) pivoted at 35 (Fig. 7) which moves slide 33 (preferably formed of an insulating material such as fiber) successively to open, close, and then agan to open switch contacts 32 (Fig. 11). Lever 34 is engaged at an intermediate point by lever I3 (by which it is operated) and adjacent its extremity bears against a shoulder 31 on slide 38. The latter is in the form of a rectangular frame having an intermediate cross member 33 adapted successively to engage spring fingers 3| and 32 carrying the respective contacts 32. A spring 33 connected to the opposite end of the slide normally causes the cross member 33 to bear against spring finger 32 to hold the contacts open (Fig. 11). Slide 38 is moved in the opposite direction by lever 34 when the shaft 31 is pushed inwardly to set the controls for interrupting the cycle. and in such position cross member 33 engages spring finger 3| thereby separating contacts 32 (Fig. 11). When released, spring 33 moves the slide first to release the finger 3| and permit closing of contacts 32 and subsequently to open the same by ilexure of finger 32.

As stated above, closin of contacts 32 energizes mechanism for rotating knob l2 to open switch I4. This mechanism may be operated by clock 23 but preferably a separate power means, in the form of a motor 35 (Fig. 5) is provided to relieve the clock of this load. When motor 35 The releasing means s is energized it rotates knob shaft through gears 91 in the interposed friction clutch 90. Rotation of the knob continues until it reaches a stop represent'ng oil position and further rotation is arrested, whereupon, inorder to avoid stallin the motor, friction clutch 08 permits slipping of the driving connection. This marks the completion of the automatic cycle. Switch 28 remaining closed, control of the heating crcuit resides solely in the thermostat and switch II and-so remains until the mechanism is reset for-an automatic cycle.

Motor remains energized only long enough to 1 of a conical cam III carriedon shaft 01 and adapted to engage the extremity III of lever III to rock the latter and release the latch. Thus untiltheshaftflispilshedintosetthefitop' 'mechanismishaft as 'eannnt'b rushed in to set the start" mechanism, I

when the timearrives for starting the cycle, registry of clutch element" with the slot in gear 35 releases shaft II to permit closing of switch 2!. Upon such release lever Ill moves outwardly into position for subsequent latchingwhen the heating period has elapsed and clutchelement 00 insure complete rotation of the control knob to I "oif position whereat 'main switch I4 is. open. The necessary t'me interval for this operation is insured in this instance by clock driven mechanism (Figs. 10 and. 11) which prevents opening of contacts 02 (after they have been closed when clutch 00 engages gear 31) until enough time has elapsed to permit rotation of knob I 2 as aforesaid. Such mechanism is here shown in the form of a pair of disk-like cam elements 99 and I0! (carrying offset notches. I02 and I03) operating in conjunction with spring finger I04 on switch slide 86 to hold the latter in intermediate position (with the contacts closed) for the desired period. When shaft 61 is pushed nwardly to permit setting of the gear 01 and stop dial 30, spring finger Ill deflects past the edges of both disks 9' and Ill, in which position it-ls' held until clutch 00 is engaged, whereupon spring 93 moves slide 08 forward untl finger I00 bears enters the slot II in gear 31, shaft 01 moves outwardly to initial position (starting the operations involved in opening main switch I4) thereby releasing lever I05 for return by spring III to latched position. I

Obviously the invention is not limited to the details of the illustrative apparatus since these may be variously modified. Moreover, it is not indispensable that all features of the invention be used conjointly since various features may be used to advantage in different combinations an subcombinations. We claim as our invention: 1. In a timing mechanism the combination comprising .a continuously running time move- I ment, means actuated by said time movement for against the under face of disk III as shown in Fig. 11. The'aforesaid disks being continuously clock driven rotate until finger Ill registers with riod to return knob If to off position regardless of its initial setting. v

The present apparatus is advantageously designed to prevent. setting of the automatic mechanism to start an automatic cycle until the mechanism has first been set thereby to place a definite limit on the heating cycle by insuring interruption of the cycle at the desired time. Such mechanism is here shown in the form of means for insuring the aforesaid sequence of setting operations. The sequence control mechanism is shown in the form of a lever III pivoted at I00 and carrying a latch element I0'I engaging shaft 00 to prevent axial movement of the latter until the latch has been released. The latch is here shown in the form of an opening I00 (surrounding shaft 50) the edge of which is adapted to seat under the face of a conical element I09 carried on shaft I9. Lever I0! is held in latched position by spring III (Fig. 7). It is only released by the inward sliding of shaft 01 necessary to set the time for interrupting the heating cycle. is here shown in the form time movement, means actuated by said beginningand ending a cycle, a first slidable shaft for setting. the beginning of a cycle, asecond slidable shaft for setting the end-of acycle, a pro- Jection on each of said shafts, a latch cooperatwith each of said shafts and adapted to pre-- v vent the projection on the first shaft from passlug said latch to perform the setting function untii after the setting of the second shafthas causeda movement of said latch.

. a. a time switch including a continuously runtime movement for beginning and ending a cycle,

a first biased slidable shaft for setting the beginning .of said cycle, a second biased slidable shaft for setting the end of said cycle, a detent onisaid first shaft, a cam portion on said second shaft, a pivoted lever having one end co-acting with said detent and the other end co-acting with said cam portion so that said first shaft cannot be moved to perform a setting function until said second shaft has been moved to pivot said lever. MARTIN n. KAEFER. EVEREI'I', S. BASSE'I'I.

- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

